Including a not originally disclosed negative feature (disclaimer) in a patent claim in order to delimit the claimed subject-matter from the prior art does not constitute an inadmissible extension of the subject-matter of the original patent application if the disclaimer does not have a technical effect.

To the relief of many patentees in particular in the chemical and biotech industries the Enlarged Board of Appeal has in its most recent decision G1-16 confirmed that undisclosed disclaimers are allowable under certain circumstances defined in the decision G1-03, namely in order to

restore novelty by delimiting a claim against state of the art under Article 54(3) and (4) EPC (later published prior art);

restore novelty by delimiting a claim against an accidental anticipation under Article 54(2) EPC; an anticipation being accidental if it is so unrelated to and remote from the claimed invention that the person skilled in the art would never have taken it into consideration when making the invention; and

disclaim subject-matter which, under Articles 52 to 57 EPC, is excluded from patentability for nontechnical reasons.

An undisclosed disclaimer is defined by including into a patent claim a negative technical feature, whereby neither the disclaimer itself nor the subject-matter excluded by it have been disclosed in the application as filed (G1-16, point 14).

The Enlarged Board of Appeal (EBA) reasoned that such undisclosed disclaimers in most cases constitute added matter, i.e. “the requirements of Article 123(2) EPC leave virtually no chance of an undisclosed disclaimer being allowable” since “introducing any disclaimer per definitionem excludes subject-matter from a claim and, hence, changes the technical content of the claim” (G1-16, point 42). The EBO allowed undisclosed disclaimers under the above-mentioned clearly defined conditions despite the fact that they violate Art. 123(2) EPC, because under these circumstances a violation of Art. 123(2) EPC would not give the patentee or applicant an unwarranted advantage damaging to the legal security of third parties; this being the rationale behind Art. 123(2) EPC (G1-16, point 36).

The German Federal Court of Justice (FCJ), however, applies in the recently published ex-parte decision “Phosphatidylcholin” a different reasoning. In the case the FCJ had to decide upon an appeal on points of law (“Rechtsbeschwerde”) of the applicant of a patent application, which has been rejected both by the GPTO and the Federal Patent Court based on the ground that of an undisclosed disclaimer consisted of an inadmissible extension beyond the content of the original application. The patent claim before the FCJ reads as follows:

The undisclosed disclaimer (feature c)) requires that the claimed preparations are free from phosphatidylcholine (a particular form of lecithin). Such preparations free from phosphatidylcholine are not disclosed in the original application documents. The GPTO and the Federal Patent Court therefore rejected the claim as inadmissibly amended, which finding was not contested by the applicant itself.

The FCJ, however, takes a different position and concludes that in the original application documents there is also no indication that phosphatidylcholine is a necessary component of the preparation or that its addition is considered advantageous. Therefore, the disclaimer “merely expresses the fact that from the large number of possible compositions of the preparation, which are possible according to the original application documents, only those containing phosphatidylcholine are excluded”. In addition, the undisclosed disclaimer merely serves to distinguish the invention over a (non-accidental, prepublished) prior art reference R disclosing skin protection preparations containing sodium chloride and glycerin in addition to the main ingredient phosphatidylcholine. The FCJ concludes that undisclosed disclaimers do not consist of an inadmissible amendment if (i) they serve the purpose to distinguish the claimed subject-matter over the prior art and (ii) the disclaimer has no technical effect. The use of undisclosed disclaimers is allowable during the examination as well as in post grant procedures.

The reasoning of the FCJ thus differs from that of the EBA. The EBO concludes: Undisclosed disclaimers constitute an inadmissible amendment but are exceptionally allowable under the above-mentioned circumstances 1., 2., or 3. The FCJ finds: Undisclosed disclaimers do not constitute an inadmissible amendment in the first place and are therefore allowable (i) if they serve to distinguish the claim over the prior art and (ii) if they do not have a technical effect.

In practice, the main difference is that under the FCJ approach the allowability of undisclosed disclaimers is also applicable to non-accidental prepublished prior art (as reference R in the subject decision “phosphatidylcholine”). Condition (ii) requires that the undisclosed disclaimer must not have a technical effect, i.e. the skilled person must not derive any new technical information therefrom. This condition seems to imply that undisclosed disclaimers are not be accepted to support inventive step. The FCJ has decided in the “phosphatidylcholine” case that the disclaimer does not have any technical effect based on the application documents without reference to the prior art, such that the question of inadmissible extension is independent from the considered prior art.

The assessment of a potential technical effect of the undisclosed disclaimer, however, may lead to the following problem:

In the present appeal on points of law case the FCJ had to refer the matter back to the Federal Patent Court to decide on the merits whether the claim containing the disclaimer is novel and involves an inventive step over the prior art. It is to be expected that novelty will be confirmed, because otherwise the disclaimer would not have made any sense. More interesting, however, is the assessment of inventive step: The closest prior art document R discloses a skin protection preparation comprising phosphatidylcholin (as main, essential ingredient) + glycerol + sodium chloride (features [C+A+B]). The application under review claims glycerol + sodium chloride + (not phosphatidylcholin), i.e. features [A+B+notC]. Would it be obvious for the skilled person starting from closest reference R to provide a skin protection preparation removing the main, essential component? Probably not. In this case, however, the disclaimer notC would indeed have a technical effect establishing inventive step, contrary to the finding of the FCJ allowing the disclaimer in the first place. It will be interesting to see how the Federal Patent Court will resolve this matter.

The EBA approach, in contrast, appears to avoid such problems: A negatively claimed technical feature is regarded as (almost) always having a technical effect such that its addition contravenes Art. 123(2) EPC, but is exceptionally allowed under certain precisely defined conditions avoiding unnecessary hardship for the patent proprietor while preserving legal certainty for third parties.